Chemical constituents of dichloromethane extract from the leaves of Gardenia angkorensis, their cytotoxic and α-glucosidase inhibition activities

Abstract

Gardenia is a genus of about 140 different plant species of the Rubiaceae family. Previous studies have shown that terpenes and phenolics extracted from Gardenia sp. showed numerous potential bioactivities. In this study, the chemical constituents of G. angkorensis, their cytotoxic and α-glucosidase inhibition activities were investigated. The phytochemical investigation of the dichloromethane extract of G. angkorensis leaves growing in Vietnam has led to the isolation of 19α-hydroxyoleanolic acid 3-Ο-β-D-glucuronopyranoside (1), chikusetsusaponin IVa, 3 β, 16 β, 21 β, 23, 24-pentahydroxy urs-12,18,20-trien-28-oic acid-γ-lactone (3), linalool glucoside and linalyl 6-O-α-L-arabinopyranosyl-β-D-glucopyranoside (5). The identities of the compounds were based on the analysis of their NMR data. Compound 1 showed moderate inhibition against α-glucosidase with IC₅₀ value of 58.01 ± 4.45 μM while compounds 3 (IC₅₀ 186.60 ± 4.68 μM) and 5 (IC₅₀ 239.53 ± 7.22 μM) exhibited weak cytotoxicity against the KB cell line and Hep G2 cell line (IC₅₀ values 180.80 ± 7.16 μM, 253.95 ± 8.14 μM).